The present invention relates to the decontamination arts. It finds particular application in conjunction with the cleaning and microbial decontamination of medical instruments and equipment and will be described with particular reference thereto. It should be appreciated, however, that the invention is also applicable to other systems in which entire outer surfaces of rack-supported items are to be contacted with a liquid.
The reuse of a wide variety of medical and dental equipment, such as endoscopes, has lead to the development of cleaning and microbial decontamination systems for ensuring decontamination of the equipment. The equipment is often unable to withstand the high temperatures or pressures of steam sterilization because of the materials used in construction. As a consequence, liquid microbial decontamination systems have recently been utilized for sterilization or disinfection of such equipment.
Commonly, a technician rinses the used equipment, then mixes a liquid disinfectant or sterilant composition and manually immerses the equipment to be microbially decontaminated in the composition. The high degree of manual labor introduces numerous uncontrolled and unreported variables into the process. There are quality assurance problems with technician errors in the mixing of sterilants, control of immersion times, rinsing of residue, exposure to the ambient atmosphere after the rinsing step, and the like. If the equipment is disinfected without cleaning, biological materials may remain on the equipment. The biological material can break down to pyrogens or other toxic substances.
Recently, systems have been developed which automate the decontamination process. U.S. Pat. Nos. 4,731,222; 5,217,698; and 5,552,115 disclose examples of such automated liquid systems. A reproducible amount of a decontaminant is delivered to the microbial decontamination system from a single dose package. U.S. Pat. Nos. 5,037,623 and 5,662,866, for example, disclose cups which contain a measured dose of either a liquid peracetic acid concentrate or powdered reagents.
To release the sterilant or disinfectant into the fluid flow path of a microbial decontamination system, the cup is inserted into a well in fluid communication with the system. The cup is opened and water is circulated through the well. The decontaminant solution formed is transported to a sterilization chamber where it is brought into contact with items to be decontaminated.
For effective decontamination, all of the surfaces of the items should be contacted with the decontaminant solution. However, to arrange the equipment in the decontamination chamber, various support members, such as clips, are generally used. These tend to impede the passage of the liquid decontaminant to adjacent regions of the equipment surfaces. To address this problem, U.S. Pat. No. 5,759,490 discloses a porous clip for shaping and positioning catheters in a countertop sterilizer. The clip is fabricated from an open-celled porous material which permits the passage of the decontaminant to the portion of the catheter gripped by the clip.
For larger items, such as endoscopes, however, it is convenient to support these on racks and spray the disinfectant over the outer surfaces, while simultaneously delivering liquid disinfectant or sterilant to the internal passageways of these items. Contact areas between the endoscopes and the racks lead to reduced access of the decontaminant. This tends to result in incomplete decontamination of the equipment.
The present invention provides for a new and improved porous rack assembly which overcomes the above-referenced problems and others.
In accordance with one aspect of the present invention, a flow-through rack assembly for supporting an item to be decontaminated is provided. The assembly includes at least one porous hanger for supporting the item, the hanger being formed of a porous material which permits a decontaminant fluid to permeate therethrough and contact the item, and a fluid flow line which supplies the decontaminant fluid under pressure to the hanger.
In accordance with another aspect of the present invention, a method of decontamination is provided. The method includes supporting an item to be sterilized on a porous hanger and spraying surfaces of the item with a decontaminant fluid. The method further includes passing a portion of the decontaminant fluid under pressure through the porous hanger to contact a portion of the surfaces of the item which is in contact with the hanger.
In accordance with another aspect of the present invention, a decontamination system is provided. The system includes a chamber for receiving items to be decontaminated and a flow-through rack assembly supported within the chamber for supporting at least one of the items to be decontaminated. The rack assembly includes at least one porous hanger for supporting the item. The hanger is formed from a porous material which permits a decontaminant fluid permeate therethrough and contact at least one item. The assembly also includes a fluid flow line which supplies the decontaminant fluid to an interior of the porous hanger.
One advantage of the present invention is that exterior surfaces of equipment are thoroughly decontaminated.
Another advantage of the present invention is that complete decontamination of several large pieces of equipment is achieved in a relatively short time.
Yet other advantages of the present invention derive from the spraying of a decontamination fluid over large items, reducing the volume of decontaminant used, as compared with immersion systems.
Still further advantages of the present invention will become apparent to those of ordinary skill in the art upon reading and understanding the following detailed description of the preferred embodiments.